1. Field of the Invention
The invention relates to a glass substrate created to have more than one type of surface. More particularly, the invention relates to a glass substrate to be used in an external rearview mirror of a motor vehicle wherein the glass substrate used to create the mirror surface includes a primary mirror surface and a blind spot mirror surface.
2. Detailed Description of the Related Art
Blind spot mirrors are common for exterior external rearview mirrors on motor vehicles, wherein the exterior rearview mirror assembly includes a primary reflector, also known as the Main Viewing Glass, and a secondary reflector also known as a Blind Spot Mirror. Automotive manufacturers often provide these blind spot mirrors on the vehicles sold because it is well known that a “blind zone” or “blind spot” exists on the side of most vehicles.
In some instances, this secondary mirror is mounted separately from the primary reflector and thus is independently adjustable from the main viewing glass. In other cases, the secondary reflector is mounted on the same carrier, or backing plate, as the primary reflector. In still another embodiment, the blind spot mirror is a concave depression on a second surface of the primary reflector within the exterior rearview mirror. While this last concept has been well established through prior art and has been so, for some time now, this embodiment is not prevalent within the marketplace because of the extreme difficulty realized in manufacturing the concave depression in the glass substrate.